Various techniques have been proposed for vehicle air conditioning control devices to be mounted on vehicles of, for example, trains to control the air conditioning in the vehicle (hereinafter also described as “vehicle interior”). The traditional vehicle air conditioning control devices detect the vehicle interior temperature, the vehicle interior humidity, and the outside-air temperature and control the air conditioning capacity on the basis of the difference between the set temperature and the vehicle interior temperature, of the vehicle interior humidity, and of the outside-air temperature.
When the outside-air temperature is high during, for example, summertime, a number of passengers get aboard the vehicle after the opening of the doors at the arrival in a station, and then, the vehicle interior temperature increases due to the air exchange at the opening of the door and to the heat emanating from the passengers.
The traditional vehicle air conditioning control devices perform so-called feedback control to enhance the air conditioning capacity with detection of an increase in vehicle interior temperature. Unfortunately, there is a time lag between the detection of an increase in vehicle interior temperature and the start of the effective air conditioning, resulting in temporary loss in the vehicle interior comfort.
Thus, with attention directed to the change in vehicle interior comfort, techniques have been devised which controls the vehicle interior air conditioning in advance by predicting, before the arrival in the next station, the temperature change at the time of arrival in the next train on the basis of the passenger load factor at the next station that is computed from the statistical predictions (see, for example, Patent Documents 1 and 2).
The vehicle air conditioning control device having the vehicle air conditioning control method disclosed in Patent Document 1 applied thereto performs a mathematical operation on an air conditioning reference temperature in the vehicle on the basis of the vehicle interior temperature, the vehicle exterior temperature, the vehicle interior humidity, and the passenger load factor of the vehicle. The vehicle air conditioning control device determines the air conditioning control pattern for providing the air conditioning in the vehicle on the basis of the air conditioning reference temperature obtained from the mathematical operation, and then, controls a vehicle air conditioning device on the basis of the air conditioning control pattern that is determined.
In particular, the vehicle air conditioning control device disclosed in Patent Document 1 provides the vehicle interior air conditioning by starting an air conditioning compressor included in the vehicle air conditioning device when the difference between the vehicle interior temperature and the air conditioning reference temperature exceeds a given value. The vehicle air conditioning control device also provides the vehicle interior air conditioning under the following condition even when the difference between the vehicle interior temperature and the air conditioning reference temperature falls below the given value.
In a case where the time between the measurement of the vehicle interior temperature and the arrival in the next station is shorter than the restart prevention time element that is predetermined for the air conditioning compressor and the passenger load factor at the next station is predicted to exceed the predetermined value, in other words, the number of passengers going on board at the next station is predicted to be over a given number, the vehicle air conditioning control device starts the air conditioning compressor before the arrival in the next station. The vehicle air conditioning control device provides the vehicle interior air conditioning by controlling the vehicle air conditioning device on the basis of the passenger load factor predicted for the next station.
Thus, even if the difference between the vehicle interior temperature and the air conditioning reference temperature falls below the given value, with the prediction that passengers over the given number go on board at the next station, the vehicle air conditioning control device disclosed in Patent Document 1 continues the startup of the air conditioning compressor during startup or starts the air conditioning compressor at rest before the arrival in the next station as long as the restart prevention time element is not affected. This provides an effective vehicle interior air conditioning and prevents the vehicle interior environment to be uncomfortable even when a number of passengers come on board at once.
The vehicle air conditioning device disclosed in Patent Document 2 controls air conditioning as described below. The vehicle air conditioning device predicts, before the arrival in the next station, the passenger load factor at the arrival time in the next station, and then, obtains a corrected temperature on the basis of the passenger load factor that is predicted. The vehicle air conditioning device obtains the air conditioning reference temperature by adding the corrected temperature that is obtained to the vehicle set temperature, compares the air conditioning reference temperature and the vehicle interior temperature, and performs the air conditioning control on the basis of the comparison results.
Thus, the vehicle air conditioning device disclosed in Patent Document 2 is configured to perform the air conditioning control corresponding to the air conditioning reference temperature for the running between the next station and the station after next before the vehicle arrives in the next station. This provides the pleasant vehicle interior air conditioning at the arrival of the vehicle in the next station and at the time of departure from the next station.
Thus, the vehicle air conditioning control device disclosed in Patent Document 1 and the vehicle air conditioning device disclosed in Patent Document 2 are configured to improve the vehicle interior comfort. Meanwhile, with attention directed to the power consumption required for the running of the train, in other words, the power-running/regenerative electric power, techniques for controlling the vehicle interior air conditioning have been devised with consideration given to energy saving and power saving (see, for example, Patent Documents 3 and 4).
The electric-train control device disclosed in Patent Document 3, which includes load control means, is configured such that the surplus regenerative power can be consumed by the load of an auxiliary power source device. Consequently, while the electric train is in the regenerative braking state, the regenerative energy can be consumed by the load of the auxiliary power source device such as a cooler, resulting in the improved energy saving.
The control device having the electric-train controlling method disclosed in Patent Document 4 applied thereto monitors the operation information including the operation conditions and the power consumption during the operation of the train. For the power-running command that is input as the operation command through an input unit, the control device forces the control command for the cooler into OFF to stop the cooler even if the input command for the cooler is ON. When the operation command is not the power-running command and the main electric motor consumes a small amount of current, the control device causes the control command for the cooler to turn into ON at the time when the input command for the cooler turns into ON. Thus, the stoppage of the cooler during power running levels the power consumption in the entire train, resulting in a reduction in the peak power of the substation, in other words, power saving.